Saturday night in London and a group of well-dressed, well-informed twenty- and thirtysomething women is having supper at a private dining club. The talk turns from how much we hate Ally McBeal and how much we love French Martinis to another, less glamorous, subject. Once the male waiter has been dispatched from the room, at least half the women confess to wearing Marks & Spencer control underwear. Considering that any self-respecting fashion follower has a drawer stuffed with frilly Agent Provocateur smalls and sleek Dolce and Gabbana Intimo numbers, this is a major admission. The underwear currently gripping the capital is large, black, nylon and heavily elasticated but, and this is the important bit, they do a very important job.

According to the rather inexact sample group gathered that Saturday night, it's worth the embarrassment of queuing at M&S Marble Arch, clutching these granny-ish garments, worth wrestling yourself into them (the elastic is seriously tight) in the bathroom, hoping desperately that you're not observed, and worth the pounds 14 a pair (pricey for good old M&S) to get into those summer skimpy dresses or slender Capri pants.

What these controllers do is squeeze you in all the right places to give the illusion of a flat tummy, a hand- span waist and pert buttocks. What happens to the excess flesh is not clear, but they do start to cut off circulation to the legs after a few hours ... and if you're expecting company in the bedroom, leave them at hom.